Engines



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NORMAN XV. VHEELERy OF NEW' YORK, N. Y.

ARRANGEMENT OF PASSAGES AND VALVES FOR CUSHIONING THE PISTON OF STEAM-ENGINES.

Specification of Letters Patent No. 19,220, dated January 26, 1858-.

To all whom t may concern Be itknown that I, NORMAN IV. IVHEELER, of thecity and State of New York, have invented a new and useful Arrangementof Passages and Valves for Oushioning the Pistons, and PartiallyBalancing the Valves of Steam-Engines; and I do hereby declare that thefollowing is a full and exact description thereof, reference being hadto the accompanying drawings and to the letters of reference markedthereon.

The nature of my invention consists in arranging check-valves inpassages, which open into the steam cylinder within the piston stroke,so that live steam from behind the piston. near the end of a strokepasses into the clearance before the piston, and into the side pipe andspaces connected therewith, thus arresting the motion of the piston,partiallv balancing the main valves, and filling the dead-space of theengine with steam which would otherwise escape from the engine and belost.

To enable others skilled in the art to make and use my invention, I willproceed to describe its construction and operation.

In the accompanying drawings, Figure 1 is a sectional view of anordinary slidevalve engine, with the cushioning apparatus attached, and2 and 3 are sectional and end views of an engine known as lVheelerspumping engine with the cushioning apparatus attached.

In Fig. l A, is the steam cylinder, B the working piston, C the pistonrod, E the slide valve, and D D the steam channels or side pipes; F andG are check-valves placed in the ports which connect the steam cylinderwith the channels D D, in such manner that after the slide-valve hasclosed the exhaust port and just before the piston has completed itsstroke it will pass over and beyond F or G and allow steam to pass frombehind it,-raising F or G, as the case may be,-into D and thence intothe clearance, thus making the pressure upon one side of the pistonequal to that 0n the other', when the check-valve F or G closes, andthere is an upward balancing presure under the slide valve,-measured bythe area of D D. Now if the piston continues its forward motion thespacebefore it will be diminished and the pressure increased therein,and when the stroke is completed, and the steam which caused itexhausted, that which passed through F or G into D, will be retained,and usefully assist in performing the following or return stroke, and soon. In constructing such engines I prefer to give less steam and exhaustlead to the main valve than is usual in ordinary practice.

In Fig. Q it will be seen that the construction and operation of thecushioning apparatus is similar, and that the piston B is represented ashaving just passed K, which should be shown as opened,) in which case itis obvious that steam would pass up vthrough K into D and D, and intothe clearance before the piston, B, thus performing its specificfunction of cushioning B and partially balancing E-(which should beshown as closed and E open)- besides an incidental function of closing Fand opening F, thus allowing the steam contained in A to escape throughI, F and H while by the closing of K the steam in the dead-space will beretained and assist in the return stroke.

I claim- Arranging check-valves in the steam passages for cushioning thepiston and balancing the steam valves with steam taken from behind thepiston substantially as set forth.

NORMAN IV. IVHEELER.

lVitnesses:

JAMES HALL, GEO W. BREGER,

